Nice list. Maybe add the 20x124mm since Japan now uses it to shoot at enemy soldiers because it is no longer an effective AT round?

One minor nit is that I think that the 6.5x55 Swedish Mauser will probably have a different name.

Quoted

Japan's heavy machine-gun round is noted solely as "13.2mm" and does not list a case length.

That's because I never bothered to look any further than navweaps for this one which IIRC does not list the case length. Looking around, OTL it is based on the French Hotchkiss so it is probably best to assume that Wesworld Japan's 13.2mm is a 13.2x96mm one (KISS).

The 6.5x50 weapons would indeed be largely phased out and replaced by 7.7x58mm weapons though there would still be some around, especially with reserve troops. Still I think it is a good caliber so the old 6.5/50mm will be replaced by a new and better 6.5mm round to be used in Japan's next rifle.

One minor nit is that I think that the 6.5x55 Swedish Mauser will probably have a different name. :)

True, and I'm pretty sure I and others have referred to it by the name '6.5x55 Nordish Mauser' in canon. I changed the name in the table, and added Note #14 to make it clear that it's the historical equivalent.

Quoted

Japan's heavy machine-gun round is noted solely as "13.2mm" and does not list a case length.

That's because I never bothered to look any further than navweaps for this one which IIRC does not list the case length. Looking around, OTL it is based on the French Hotchkiss so it is probably best to assume that Wesworld Japan's 13.2mm is a 13.2x96mm one (KISS).

Okay, that makes sense. I changed the Japanese entry for 13.2mm to read 13.2x96 Hotchkiss, and updated Note #10 to clarify the equivalency.

I did a little more research and determined that, historically, the Danes used the Krag-Jorgensen rifle chambered in 8x58R Krag. I put this in the table as an Uncertain.